Aviator&#39;s breathing oxygen duration indicator



Oct. 13, 1959 A. BLOOM I 2,908,167

AVIATOR'S BREATHING OXYGEN DURATION INDICATOR Filed Feb. 11, 1957 2 Sheets-Sheet 1 Oct. 13,1959 A. BLOOM. 2 ,908,167

AVIATORS BREATHING OXYGEN DURATION INDICATOR Filed Feb. 11. 1957 2 Sheets-Sheet 2 INVENTOR. 30 6012p Q9/0007 ZZZ-Tl;

2,968,157 :Pate'nted Oct. 1 3, 1'959 AvrA'roms BREAnnNo oxronN "DURATION INDICATOR JAQYOI! Bloom, Pa'sadena, Calif. Application'February 1 1, 1957,;Sei iaLN0. 639,590

g 2 Claims. (Cl. 73-393) (Granted .under rare as, uscode 19:52 sec. 266) The invention described herein may-be manufactured H "and usediby or for the Governmenttofrthe Unitedifitates ".fif America for governmental purposes without :the :pay-

ment of any royalties thereon or therefor.

This invention relates to a device which automatically indicates the amount of breathing oxygen left in an aviators supply container. In prior art devices, the aviator was left to his own resources to determine how much oxygen remained in-the supply. The aviator had to compute his remaining supply by reading the pressure gage on the supply and making compensations for a given altitude or mean altitude and for his breathing rate and tidal volume.

The object of this invention, therefore, is a device which automatically indicates to an aviator the amount of oxygen remaining in his oxygen supply.

A further object of this invention is an oxygen-supply indicating device which compensates for the altitude of the supply container.

A still further object of this invention is in an oxygensupply indicating device which is relatively inexpensive to manufacture, inexpensive to maintain and is readily portable allowing for constant re-use of the indicator.

These and other objects will be apparent to those skilled in the art from a reading of the following descriptive matter together with an examination of the attached drawings wherein:

Figure 1 is an elevation View of the instant invention,

Figure 2 is a cross-sectional view along section line 22 in Figure 1,

Figure 3 is a cross-sectional view along section line 3-3 of Figure 1,

Fig. 4 is a plan view of the invention, and

Fig. 5 is a sectional view along the line 55 of Fig. 4.

Referring to Figures 1 and 2, an upright support fitting 1 has its lower section 25 threaded for attachment of such fitting to the oxygen supply, for example, the oxygen bottle 34 fairly standard in military aircraft. The interior of the support fitting 1 is hollow for a portion of its length from the threaded end (see Figure 3) for transmission of the oxygen pressure to the hollow Bourdon tube connected thereto.

The upper section 3 of the fitting 1 above the hollow or bore is cut away longitudinally to provide a fiat support face 40 for the remainder of the instrument. Attached to the opposite side of cut away of support face 40 of the section 3 is an L-shaped bracket 2 with the longer of the two legs of the L being approximately normal to the axis of the fitting 1. Projecting upward from the leg parallel to the fitting 1 are supports 7 spaced apart for mounting of the altitude compensator. Supports 7 are secured to the L bracket by any conventional means.

A cradle or rocker 4 is rotatably pivoted to the inner faces of supports 7; the cradle is in the form of a modified U with the legs of the U pivoted about bearings in the supports 7. On the inner face of the base of the U an aneroid barometer 6 is mounted with a pivot arm 11 attached thereto; thus, the arm 11 is able to reciprocate altitude.

.2 rinzresponsezto :tlre changesinihe atmospheric pressure or The (reciprocations nof (the pivot arm 11 are transferred rte 7B. rotary motion at :sleeve I gear through curved surface on which tare cutnagplurality ofirack teeth 113 which mesh with the gear :teeth on sleeve gear 14. .An iindicatorrshaft 5 :passes through .the uprights 7 and nthercr'adle hand-is rotatably journaleditherein;ito the s ha'ft .5 iis mounted (the "sleeve .gear :14 thereby imparting any v rotations ureceived from the ipixtotfiarm J11 .v-ia 'link :12 and track 313 :to .the rrotatablec'shaft 5.

2A mod :24 us attaohed to the -:ends of the U-shaped cradled zand :acts :as :a :cnunterhal'ance weight for structure associated adjacent the zbzazrometer 26,:ite. :the entire =cradle :Refemzing tto rFigures l1 and is, :a lB'ourdon "tube 15 has some :enid attached [t0 ztheifitting 1 wi'th ihesinterior of the tube in communication with the hollow interior 37 of the fitting. The tube is in its customary circular shape and the movement of the unattached end of the tube is an indication of the changes in the pressure within the oxygen bottle. The free end of the tube transmits its motion to connecting links 19,18; the latter link is coupled to rocker arm 20. The arm has an elongated slot 21 at one end thereof allowing a change in the position of link 18 thereby altering the leverage ratio; the opposite end of the rocker arm has a row of rack gear teeth 22 thereon meshing with gear wheel 23. The rocker arm is supported on a shaft 31 disposed between a pair of plates 16, one of which plates is fastened to the cut-away or flat face 40 of the upper section 3' of fitting 1 and to which the other plate is secured at a spaced distance by means of bushings 30.

A shaft 32 is journaled in the upper section 3 of the support fitting 1 and is also journaled in the spaced plates 16f On the opposite side of the face 40 on the upper section 3, the shaft 32 is secured to a connecting arm 8; the arm in turn is directly coupled to the cradle 4 via a rod 9. Thus, since gear wheel 23 is mounted on shaft 3 2, the drive it receives from the rocker arm 20 is transferred to the rocker 4 via the connecting links 8, 9. A spring 17 maintains the shaft 32 and rocker 4 under the proper tension. The rotary motions received by the rocker 4 are transferred directly to the pivot arm 11, link 12, rack 13, wheel 14 and dial shaft 5. The dial shaft 5, therefore, receives actuation from two sources, the first from the Bourdon tube through the cradle 4 and the second from the aneroid barometer 6. Each motion is superimposed upon the other as they both travel through arm 11, link 12 and gear 14.

The indicator shaft 5 has mounted on one end thereof a pointer 26 which has associated therewith a circular face ,27 mounted on bracket 2; the face is numbered to read hours and minutes denoting the amount of breathing time left using the oxygen supply.

The unit has been designed upon the assumption that the users lung'volume and breathing rate are average; it is further assumed that the users breathing rate. and lung volume remain approximately the same regardless of the altitude at which the plane is at. Upon these assumptions the pressure in the Bourdon tube is calibrated in relation to time and the aneroid barometer corrects for the altitude secured to said shaft and movable with said shaft, a'

cradle rotatably mounted on said shaft, a connecting link pivotally mounted on said cradle and operatively connected at one end to said shaft for rotating same and the pointer thereby when said link is pivoted, an aneroid barometer mounted on said cradle and operatively connected to the other end of said link for pivoting said link in response to changes of atmospheric pressure, a connecting arm coupled at one end to said cradle for rotating said cradle thereby causing corresponding rotation of said pointer by way of said barometer, link and shaft when said arm is rotated, a support fitting provided with a passage and secured to said support means for coupling said meter to a source of oxygen, a second rotatable shaft fixed to the other end of said connecting arrn rotatably supported by said fitting for rotating said ann, means for rotating said second shaft in response to the pressure of.

said oxygen supply comprising, a rocker arm pivotally mounted on said fitting operatively connected at one end to said second shaft for rotating same, a Bourdon'tube .4 secured to said fitting at one end with its passage communicating with said fitting passage and operatively connectedrat its other end to the other end of said rocker arm, whereby movement of said Bourdon tube under influence of pressure of said supply of oxygen is effective to pivot said rocker arm and pointer thereby.

2. The meter of claim 1 in which a'dial is provided adjacent said pointer on said support means, said 'dial being graduated in units of time over which said pointer is movable, a gear wheelfixed on each of saidfirst' and second shafts, said "ends of said connecting link and rocker arm which are operatively connected with the shafts are provided with rack teeth meshing with their respective gear wheels. i

References Cited in the file of this patent UNITED STATES PATENTS 1,376,505 Berry May 3, 1921 1,413,514 Berry Apr. 18, 1922 1,856,079 Mott May 3, 1932 2,399,448

Nyquist Apr. 30, 1946 

